Lab Objective:
Learn how to use the Dig command to gather DNS information.
Lab Purpose:
Dig stands for Domain Information Groper. It is a tool for querying DNS nameservers for information about host addresses, mail exchanges, nameservers and related information.
Lab Tool:
Kali Linux.
Lab Topology:
You can use Kali Linux for this lab.
Lab Walkthrough:
Task 1:
Dig is a tool which can be used on either Linux or Mac OS. Dig comes pre-installed on Kali Linux and you can check its version using the following command:
dig -v
The dig syntax looks like the following:
Dig [server] [name] [type]
We will begin by performing a simple dig command. Type the following into a terminal:
dig google.com
Task 2:
The above command will include several information. There may be a time when you only want the
result of the query. This can be achieved in dig with the following command:
dig google.com +short
As you can see, there can be more than one IP for a host record.
Task 3:
This next command will get rid of all information before the answer section, for easier reading. We can specify this using the following command:
Task 4:
We can also specify the nameservers we wish to query using the following command:
This command queries the “google.com” record from the Name Server with IP address 8.8.8.8.
Task 5:
If we want to query all DNS record types, we can use the “ANY” option. This will display all the available record types in the output:
Task 6:
We can also look up a specific record. For example, if we want to get only the mail exchange section associated with a domain, we can use the following command:
dig google.com MX
We can query a number of specific record types using the following tags in place of MX:
TXT, CNAME, NS, A
Task 7:
We can trace the DNS path, similar to traceroute, using the following command:
Task 8:
It is also possible to make DNS queries for IP addresses.
Task 9:
Dig has a useful feature which allows you to perform a number of DNS lookups for a list of domains instead of doing the same for each one individually. This can be done by performing a lookup using a file:
dig -f domain_names.txt +short
Task 10:
It is possible to access domain verification data by making a DNS TXT query.
Dig is a tool with multiple uses and can be very useful for gathering a broad range of DNS information about a target site.
